There are presently a number of methods and techniques for connecting biological structures. These techniques generally involve suturing the structures together as is the case in vascular surgery, gastrointestinal tract surgery, urological surgery, etc. Attempts have been made to find the ideal suture material since this material acts as a large foreign body and may stimulate fistula formation, necrosis of the wall of the biological structures and a reaction from the tissue itself. Similarly attempts have been made to vary the anastomotic technique using single layer or double layer closure to obtain a better anastomosis.
The realization that the suture technique requires time and produces tissue changes which are long lasting was evident. The length of time of surgery or other procedures is important to the ultimate well being of the patient, concomittantly the quality of the anastomosis is important to the patient's long term future.
Attempts have been made to use stapling devices to join structures. These devices generally evert the tissue edges and staple them with metal pins or staples. These devices have been useful for large structures but have not been of much use for small blood vessels or fine structures.
The use of the laser to join blood vessels has been attempted. Different lasers have been tried. Two major problems exist. The first entails the fact that the laser provides spot fusion and therefore is time consuming since one must go over the entire anastomosis point by point. Secondly since the laser burns from superficial downwards it is difficult to control the energy level properly and often only the outer layers are fused which leads to aneurysm formation in thick vessels. Too deep penetration will burn through the vessel. These two points are major drawbacks to the current use of the laser.
Absorbable devices have been described to unite vessels by everting the tissue and holding them connected (Daniel et al)(Plastic and Reconstructive Surgery, Vol. 74, No. 3. Sept., 1984). However these devices require bulky connections. In addition the device requires a large amount of tissue handling with eversion and crushing of tissue. The device requires time to insert and cannot be used for and to side or side to side anastomosis. This device also in its pull through and eversion of tissue uses up quite a bit of length of the vessel in everting the tissue and can create tension. Tension in an anastomosis is often a cause of problems. This device also cannot handle large size discrepancies between vessels.
A safe and effective method of connecting biological structures has been the goal of investigators for a substantial period of time. Such a technique to be successful must allow for a good biological healing of the connected structures, performed in a very short period of time, connect all depths of the edge of the biological structure evenly, not require spot by spot welding of tissue, avoid tension on the anastomosis, avoid the use of bulky instrumentation in the biological tissue, be capable of use in end to side and side to side anastomosis and be able to handle size discrepancies and unusual anatomy.
The ability to excite particles in biological tissue has been shown (Gordon, et al). The edges of the biological structures will take up the particles by passive means or the particles may be injected. This may be at the time of connection and/or prior to the formation of the connection of the biological structures.